1. Field of the Invention
The present invention relates to a pad structure and a display device having the same.
2. Description of the Related Art
There continues to study for developing a performance of various flat panel displays such as thickness slimming, weight lightening, low power consumption and the like.
Various flat panel displays such as a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), an electro luminescence display device (ELD), an electro-wetting display device (EWD) and an organic light emitting display device (OLED) have been used recently.
In general, the flat panel display includes a display panel, a gate driver, a data driver, a timing controller and a voltage generator. The display panel defines each pixel at each crossing portion of a plurality of gate lines and a plurality of data lines. The gate driver drives a plurality of gate lines. The data driver includes a plurality of data driving integrated circuits which drive the plurality of data lines. The timing controller provides the gate and the data drivers with various control signals. The voltage generator generates reference voltages and provides the data driver with them.
The gate driver may be built in a non-active area of the display panel and the plurality of the data driving integrated circuits are mounted on a film in a manner of a chip on film (COF) in order to reduce the volume of the flat panel display and the manufacturing cost.
Various signal line, the gate driver, the data line and the like are integrated into the display device, and trend to minimize them. Accordingly, the design margin required for the manufacturing process of the components becomes insufficient and precise alignment technique is required.
In case of the data driver, two or more contact holes are formed so that the design margin shortage may result in increasing the contact resistance according to minimization of the contact hole. A steep step is caused by overlapping the contact holes so that there may happen the disconnection defect between the data driving integrated circuit and the film on which it is mounted.